Thrombectomy is a procedure for removing thrombus from the vasculature. Mechanical and fluid based systems are used to remove thrombus and accordingly open clogged or partially clogged vessels. With fluid based systems an infusion fluid including one or more of saline, lytics and the like is infused to a treatment area of a vessel with a catheter, for instance a thrombectomy catheter. The hydrodynamic force of the infusion fluid and optionally the characteristics of the lytics dislodge thrombus and accordingly open the vessel.
In one example, the infusion fluid is delivered to the thrombectomy catheter in a pulsed manner with a pump including a single piston. The piston is moved in a first direction to draw fluid into a cylinder, and then moved in a second direction to push the fluid out of the cylinder to a treatment feature of the thrombectomy catheter (e.g., an orifice). The pulses of fluid generated by the piston pump are then discontinuously applied through the treatment feature of the thrombectomy catheter to dislodge thrombus from the vessel wall. Optionally, the cylinder is prefilled with a fluid (e.g., contrast fluid or infusion fluid for thrombectomy) and the piston is driven in a single direction to gradually infuse the fluid. Upon full delivery of the fluid the cylinder must be refilled before operation is continued.
In another example a multi-cylinder pump including a plurality of corresponding pistons are coordinated to provide a continuous flow of infusion fluid. Stated another way, the plurality of pistons are operated out of sync with one another to ensure that as one of the cylinders is filling with infusion fluid another of the cylinders is providing infusion fluid output. A mechanism (e.g., a software algorithm, mechanical mechanism or the like) is used to coordinate the pistons in this manner.